Eyeglasses with variable power across their whole viewable area offer a useful function in situations found in both the developed and developing world. For example, in the developing world, a single model of eyeglass with an appropriate optical power range can be used to correct refractive error in a large section of a population. Such a model may be deployed with little direct involvement by an eyecare professional in the installation process (self refraction reference). The same or similar model can also be used to correct presbyopia amongst adults of forty years of age or more in both developing and developed world situations assuming that model can provide a modest range of positive optical power. Furthermore a variable power function may be advantageous to presbyopic persons as it will allow the wearer to adjust the power of the eyeglasses to suit various tasks such as reading, sewing or other close work.